1. Introduction 195 2. Masses and Lifetimes of π and μ Mesons 196 3. The Spectrum of the Electrons from π → μ → e Decay and the Asymmetry of the Spatial Distribution of the Electrons 197 4. The Helicities of the Leptons and the Law of Conservation of Leptonic Charge 206 5. The Magnetic Moment of the μ Meson 208 6. Electronic Decay of the π Meson. Searches for Radiative Decays of π and μ Mesons 211 7. The Depolarization of μ Mesons 217